In order to solve the problems of low automation, low precision and high reagent consumption in the process of flotation dosing, this paper presents a design scheme of the automatic dosing device with peristaltic pump as actuator. The device has a simple structure and is mainly composed of a medicine storage box, a impurity removing device and a protective cabinet body. This paper designs an experiment to investigate the control precision and the adaptability to the change of flow rate of the device. The experimental results show that the device has high control precision and strong adaptability, and it is suitable for accurate dosing of small flowrate reagents in flotation process.